Generally, in manufacturing semiconductor devices, after all wafer level processes are completed, the semiconductor devices, e.g., integrated circuits, formed on a wafer are inspected to determine whether or not the semiconductor devices have required electrical characteristics. In this wafer inspection process, a probe card having a plurality of needle-shaped contactors is used as an inspection jig.
In order to perform the wafer inspection, the probe card and the wafer are aligned such that the contactors are respectively made to face corresponding electrodes of a surface of the wafer and, then, a proper press-contact is made therebetween. After leading ends of the contactors are brought into contact with the wafer surface, the contactors are relatively pressed by a predetermined stroke, i.e., by an overdrive amount. Accordingly, the leading ends of the contactors are respectively brought into pressure-contact with the corresponding electrodes while breaking a protective film or a contamination film on the wafer surface.
Recently, there is developed a wafer inspection apparatus that allows a wafer to be inspected by one of a plurality of probe cards provided in an inspection chamber while another wafer is being transferred, pressed against or separated from another probe card by a common transfer robot or a common moving table. In this wafer inspection apparatus, one moving table is commonly used for the multiple probe cards and, thus, a configuration of a prober, especially around a wafer support or a chuck top, becomes simple. Further, the integration of probers and the space efficiency are considerably improved (see, e.g., Japanese Patent Application Publication No. 2002-22768).
In the above wafer inspection apparatus having one moving table commonly used for a plurality of probe cards, when the wafer on the chuck top is brought into press-contact with each of the probe card, there is formed a sealable surrounding space for applying a vacuum attractive force to a gap between the probe cards and the chuck top.
In order to form such a surrounding space, a vertically extensible/contractible cylindrical member, e.g., a bellows, is provided around each of the probe cards. Upon completion of the position alignment between the probe card and the wafer, the surrounding space is sucked to vacuum in association with or in response to the lifting of the chuck top by the moving table. Accordingly, an upward force is generated by a pressure difference between a pressure (negative pressure) in the surrounding space and an ambient pressure (atmospheric pressure) and applied to the chuck top. Due to the upward force caused from the vacuum attractive force, each contactor of the probe card can be stably in pressure-contact with each corresponding electrode pad on the wafer surface by a predetermined pressure.
The vacuum attraction of the surrounding space is desirably carried out at a high speed and in a short period of time to shorten a required time or a tact for the wafer inspection. However, if the surrounding space is depressurized to a set pressure (negative pressure) at a high speed, the pressure in the surrounding space shows an undershoot waveform and exceeds an absolute value of the set pressure. The contactors or the electrode pads are easily damaged by an excessive vacuum attractive force.